Once in your lifetime you will be A Bridesmaid and have sex with A Groomsman.
The Two of You will have flirted the night before at the rehearsal dinner, fortifying the possibility of “fooling around”. He will be “on break” with his "girlfriend" who just so happens to be the "bitch" who wreaked havoc on your life sophomore year in college.
You and The Groomsman will do it in a hotel or at his place enabling you to leave as soon as It’s over.
In the depressing gray light of the morning, you will remember how his ex’s ex had broken up with her to be with you who didn’t want to be with him at all and you feel even guiltier for sleeping with The Groomsman even though He said (They) were on break.